packaging: build: devenv: remove files installed previosly
packaging: build: devenv: remove files installed previosly

with increasing changes in packaging, and people that preserve their
prefix, we need a solution to cleanup old installed files if are missing
from new installation to avoid conflicts.

a method of storing a file list of all simple files (these that are
copied recursively) is a simple and efficient for this cause.

files are relative to PREFIX so that if people move PREFIX to other
location we won't erase wrong files.

Change-Id: I2b0f47ee6fa4b3fb6759bc4f4899092f4128ced7
Signed-off-by: Alon Bar-Lev <2e3ceb4d37adc6ae3ccc00d3646e0e0a036ace03@redhat.com>

zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,yapengsong/ovirt-engine,walteryang47/ovirt-engine,zerodengxinchao/ovirt-engine,walteryang47/ovirt-engine,yingyun001/ovirt-engine,yingyun001/ovirt-engine,yingyun001/ovirt-engine,OpenUniversity/ovirt-engine,walteryang47/ovirt-engine,walteryang47/ovirt-engine,OpenUniversity/ovirt-engine,eayun/ovirt-engine,yapengsong/ovirt-engine,OpenUniversity/ovirt-engine,halober/ovirt-engine,eayun/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,yingyun001/ovirt-engine,yapengsong/ovirt-engine,halober/ovirt-engine,OpenUniversity/ovirt-engine,yapengsong/ovirt-engine,yingyun001/ovirt-engine,halober/ovirt-engine,eayun/ovirt-engine,walteryang47/ovirt-engine,eayun/ovirt-engine,eayun/ovirt-engine,halober/ovirt-engine,zerodengxinchao/ovirt-engine,yapengsong/ovirt-engine